Mini-lathe POWER FEED - DIY

[machining 4 all]

Finally I completed the assembly step of my power feed. I carried out this project without making any changes in the physical structure of the machine (hole, thread, weld, cut, etc.). I was able to install the automatic control using only scrap material. I will soon show you the mechanism in operation. If you are interested, be sure to follow my updates!

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https://www.youtube.com/channel/UCqw...E3eBi7w/videos

Thank you, M4A!

[Crusty]

I used a Dodge Ram wiper motor for the power feed on my milling machine and a year later it's still doing what I need it to do. In the motor there are 3 brushes, a common, a low speed and a high speed brush which produce 2 speeds but I found that if you isolate the common from the case (which connects back to the battery negative) then you can apply power across the low and high speed brushes and get a third fastest speed. I used a 3 gang, 6 position rotary switch to control it and I have 3 table speeds in each direction. I included a power switch for off and limit switches at each end of the table's travel to automatically stop the drive at each end and with an adjustable spindle speed I can adjust it for a good cut at any particular table feed.

Here it is before I wired it up. There's a stub shaft on the end of my lead screw connected to a deep socket and a hex stub connected to the motor and the motor assembly slides in or out on pins to engage or disengage the feed. I included a brass shear pin in case of motor stalls but I suspect that the plastic gear inside the motor protects the shear pin so I always keep my thumb on the off switch.

Wiper motors deliver a surprising amount of torque and are handy and affordable for a variety of projects.

[machining 4 all]

Thanks for the comment Crusty! My version is unlike any you've seen... If you are interested, wait for my updates!

[Nitrous]

Thanks for the comment Crusty! My version is unlike any you've seen... If you are interested, wait for my updates!

is there a way to disengage the motor when you want to manually move the wheel?
I saw one a few years ago that used an electromagnetic clutch that was only engaged with 12vdc.

Great project!
Doug

here is an example: https://www.aliexpress.com/item/4001...B&gclsrc=aw.ds

[machining 4 all]

Thank you for your interest Nitrous! Yes, it is possible, but in this project this is done mechanically, when it is necessary to perform a quick return. I did not use any electrical device in this project (except the wiper motor, of course).

[Paul Alciatore]

Wiper motor, what an interesting idea. It is DC so it is reversible. Looks like a geared motor so slow speeds are possible. A quick check showed some are available for under $25. Sounds like a great choice for projects.

One question, does the average wiper motor have a back and forth mechanism built in or is that normally separate from the motor itself?

And that is a great project. Make lots of chips with it.

[machining 4 all]

Thank you for your interest Paul Alciatore! In general, a motor wiper has a mechanical part (crown and screw with worm thread) and an electronic part (controller board). Depending on the model, it can work separately, without making the movement back and forth (which is performed by a disc and by contactors). If you have access, in the junk you may be able to find it for a friendlier price or even for free!



https://www.sw-em.com/Windshield%20Wiper%20Systems.htm

[Toolmaker51]

Compliments to machining 4 all with his power feed adaptation; perfect example of what HMT.net is all about.

The Dean Kamen and Woodie Flowers program, FIRST Robotics, makes tremendous use of automotive 12v motors from wipers, windows, seats...The variety of actions available is widespread, adaptable, economical and compact.
I command (heartily encourage) any who think our young need mentoring to foster mechanical aptitude, science and/ or technology to engage with a FIRST chapter near you. I can't really see how the type of readership HMT.net has, could resist participating.

https://www.google.com/search?client...FIRST+Robotics

https://en.wikipedia.org/wiki/For_In...and_Technology

It's a rabbit hole you can literally and physically dive in to, compared to just reading about others work...

[machining 4 all]

Toolmaker51, thank you for your interest and comments!

[DIYSwede]

I second that - wiper motors are cheap, rugged and readily available at car junk yards for a few bucks.
Their cast-in mounting holes makes them easily adaptable to anything needing up to 300 rpms.
Note that for running it in reverse you'll preferably need to rework the bearing housing
to take up the tendency of the worm pushing the gear outwards against the axle end.

Personally I salvage all I can get my hands on from work, where motorized office desks occasionally get scrapped,
while suffering from onboard electronics failures, the motors aren't even run in, as descibed in this post:

Very powerful gearbox from wiper motor.

Note: These KSV 5035s have NO steenkin' fancy internal interrupt switches, no field windings or high-speed capabilities,
just plain vanilla (75-150W @ 100% DF) PM DC motors that'll take the juice and run with amazing torque for such a small unit.
Also note: While these motors come from the heavy duty 150 kg max load office pillars,
the lighter duty office tables of the IKEA and the like brands have much smaller motors (by Ketterer & Elvi for instance)
which only has 10-20% DFs (usually stated 1 min on, 4-9 mins off...),
which means that they'll get pretty hot after some 15 minutes of use as a power lead screw for my 7x14" mini lathe:

-Yet another mini lathe power leadscrew drive... For the love of ...

The biggie ones however, (>2" dia) take some real abuse (300-400% temporarily), I've braked them to standstill at max V and A
and I've never even shredded any of the Delrin worm gears inside. Never had a brush fail or wear out either,
they're designed in the fifties after all, and built ever since for continous duty truck & bus wipers
and the bare-bones (w/o worms) KP 5035 motors have been running as car, truck & bus defroster fans for decades...

Good enough for my zero-budget instant prototypes at work: motorized camera dollies, smallish hoists, turntables
or other portable stuff which cannot have an attached mains cable - powered instead by some series connected 10 Ah SLA batteries
salvaged when the whiz kids in the IT dept change their UPS batteries every other year.
Speed control thru a 10 buck Chinese (2 kW: max 50V & 40 A) PWM board w pot, via short 12 AWG cables to the motor,
makes for safe, hassle- and smokefree operation at stable revs nearly independent of axle power loading.

2 cents
Johan